Topic 4: Cell Cycle - Mitotic (M) Phase

Question 1

What is mitosis?

Answer 1

• division of nuclear material (xmes)

Question 2

What are the 4 phases of mitosis?

Answer 2

1. prophase
2. Metaphase
3. Anaphase
4. Telophase
   4 phases but a continuous cycle!

Question 3

What is cytokinesis? (3)

Answer 3

• division of the cytoplasm
• not part of mitosis
• starts when late anaphase occurs

Question 4

What occurs in cytokinesis? (3)

Answer 4

• mitosis and cytokinesis complete
• daughter cells go into interphase (G1)
• cycle starts over

Question 5

What occurs in prophase? (5)

Answer 5

1. chromosomes condense (thicken, coil) from chromatin form - become individually visible
2. nucleoli disappear and nuclear envelope breaks up
3. centrosomes move to either pole
4. Microtubules form spindle apparatus (starting at centrosomes) and attach to kinetochore proteins (called kinetochore microtubules)
5. Spindle moves xmes toward cell equator

Question 6

What occurs in metaphase?

Answer 6

• 46 xmes line up on cell equator

Question 7

What occurs in anaphase? (4)

Answer 7

1. as the spindle microtubules shortens, the kinetochores are pulled away from each other
2. causing separation of centrosomes which results in separation of the chromatids
3. 46 chromatids migrate to each pole
4. cytokinesis begins

Question 8

What occurs in telophase? (3)

Answer 8

1. xmes uncoil to chromatin
2. nucleoli and nuclear envelope reappear
3. spindle disassembles
   - cytokinesis completes or may end